SPID#: 50 The objective of this project is to maintain breeding populations of three species of nonhuman primates which contribute to the Center's AIDS Animal Model Project and to manage these populations to promote optimal breeding. The specific goal is to provide for long term colony maintenance and to produce sufficient progeny to meet the Center's requirements related to AIDS research from this dedicated breeding effort. In support of this effort, programs are in place to provide for behavioral management, serum banking, genetic analysis and B-virus screening. Breeding productivity was excellent in all three species during this project period. DNA profile have been conducted on the pigtail and mangabey populations in order to provide genetic characterization of the colony, to assign paternity to recent offspring and to determine the relative relatedness within and between two populations with quite different histories. Screening for herpes B-virus continued with fifty additional juvenile rhesus monkeys identified as negative and recruited into the program. The oldest identified negative population (born in 1992) has been formed as a B-virus negative breeding group and is expected to product progeny in 1996.